Software :: Script Calls Another Script Which Calls 'bash' Inside

I need to write a script. In which, the 2nd part commands need to run under another bash shell environment.The enter_antoher_bash_env.sh will setup a new shell environment, call "bash". The rest commands need to run under the new env. (I cannot change this script too. )If I run these command one by one manually, it works of course. If I put them into a script, enter_another_bash_env.sh won't return because it calls "bash" command inside.